A touch panel device is a device in which information can be input into an instrument as a result of a finger or pen touching the touch panel surface. In recent years, capacitive touch panel devices, which have good detection sensitivity and excellent operability, have been used in various types of devices. In particular, capacitive touch panel devices, which can accurately detect the coordinates at which a finger or pen contacts the touch panel surface, are widely used.
Capacitive touch panel devices include a plurality of drive lines and a plurality of sense lines. A plurality of X axis direction sense electrodes are provided on the respective drive lines, and a plurality of Y axis direction sense electrodes are provided on the respective sense lines. In a capacitive touch panel device, driving pulse signals are output to the drive lines in a sequential manner, and changes in an electric field between the X axis direction sense electrodes and the Y axis direction sense electrodes are detected. In other words, by detecting signals in the sense lines that correspond to changes in the electric field between the X axis direction sense electrodes and the Y axis direction sense electrodes, the coordinates at which the finger or pen contacted the touch panel surface are detected in the capacitive touch panel device.
In a touch panel display device, colored regions that have been colored black or the like are provided to the periphery of the region in which the touch panel is disposed in order to ensure that wiring patterns, which electrically connect to the sense electrodes of the touch panel in order to output driving pulses to the sense electrodes of the touch panel, are less visible. By disposing the wiring patterns for electrically connecting to the sense electrodes of the touch panel below the regions that have been painted black or the like, it is possible to realize a touch panel display device in which the wiring patterns are less visible and that has an excellent appearance.
In such a touch panel display device, it is necessary to provide the regions painted in black or the like to the periphery of the touch panel in order to decrease the visibility of the wiring patterns that connect to the sense electrodes of the touch panel. In other words, in a touch panel display device such as that described above, there is dead space at the periphery of the touch panel, and it is difficult to realize a touch panel display device with a narrow frame.
In order to decrease the dead space at the periphery of the touch panel, in the touch panel device disclosed in Patent Document 1 (Japanese Patent Application Laid-Open Publication No. 2012-150782), for example, the wiring patterns that electrically connect to the sense electrodes of the touch panel are provided inside the touch panel. FIG. 15 shows a schematic configuration diagram of a touch panel device 900 realized by using the technology disclosed in Patent Document 1. As shown in FIG. 15, an X axis and a Y axis are set.
As shown in FIG. 15, the touch panel device 900 includes: a substrate 901; a touch panel TP9; and a terminal group 902. X axis direction sense electrodes X91 to X94 and Y axis direction sense electrodes Y91 to Y94 are provided on the touch panel TP9.
As shown in FIG. 15, the terminal group 902 includes: X axis direction sense electrode terminals Tx91 to Tx94 that are respectively connected to the X axis direction sense electrodes X91 to X94; and Y axis direction sense electrode terminals Ty91 to Ty94 that are respectively connected to the Y axis direction sense electrodes Y91 to Y94.
In addition, as shown in FIG. 15, wiring patterns (a wiring pattern extending from a connecting point Cx91 to a connecting point Ce91, a wiring pattern extending from a connecting point Cx92 to a connecting point Ce92, a wiring pattern extending from a connecting point Cx93 to a connecting point Ce93, and a wiring pattern extending from a connecting point Cx94 to a connecting point Ce94) for connecting the X axis direction sense electrodes X91 to X94 and the X axis direction sense electrode terminals Tx91 to Tx94 are provided in the touch panel device 900.
The wiring pattern extending from the connecting point Cx91 to the connecting point Ce91 is electrically connected to the X axis direction sense electrode X91 at the connecting point Cx91, and is connected to the X axis direction sense electrode terminal Tx91 at the connecting point Ce91 via wiring provided on the substrate 901.
The wiring pattern extending from the connecting point Cx92 to the connecting point Ce92 is electrically connected to the X axis direction sense electrode X92 at the connecting point Cx92, and is connected to the X axis direction sense electrode terminal Tx92 at the connecting point Ce92 via wiring provided on the substrate 901.
The wiring pattern extending from the connecting point Cx93 to the connecting point Ce93 is electrically connected to the X axis direction sense electrode X93 at the connecting point Cx93, and is connected to the X axis direction sense electrode terminal Tx93 at the connecting point Ce93 via wiring provided on the substrate 901.
The wiring pattern extending from the connecting point Cx94 to the connecting point Ce94 is electrically connected to the X axis direction sense electrode X94 at the connecting point Cx94, and is connected to the X axis direction sense electrode terminal Tx94 at the connecting point Ce94 via wiring provided on the substrate 901.
As can be seen from FIG. 15, the wiring pattern extending from the connecting point Cx91 to the connecting point Ce91 is provided such that the wiring pattern is substantially parallel to the border on the wiring pattern side of the Y axis direction sense electrode Y91 in a region near the Y axis direction sense electrode Y91. In other words, the wiring pattern extending from the connecting point Cx91 to the connecting point Ce91 and the Y axis direction sense electrode Y91 are provided so as to extend substantially parallel to and near each other (sandwiching a region formed of an insulator (or a dielectric)); thus, there is an increase in the parasitic capacitance generated between the Y axis direction sense electrode Y91 and the wiring pattern extending from the connecting point Cx91 to the connecting point Ce91.
In addition, parasitic capacitance is generated for the same reason for each of the following: (1) the Y axis direction sense electrode Y92 and the wiring pattern extending from the connecting point Cx92 to the connecting point Ce92; (2) the Y axis direction sense electrode Y93 and the wiring pattern extending from the connecting point Cx93 to the connecting point Ce93; and (3) the Y axis direction sense electrode Y94 and the wiring pattern extending from the connecting point Cx94 to the connecting point Ce94.
In this manner, in the touch panel device 900, it is possible to decrease the amount of dead space at the periphery of the touch panel since the wiring patterns for connecting to the X axis direction sense electrodes are provided inside the touch panel TP9.